Bisphenol-A (2,2-bis(4-hydroxyphenyl)propane, or “BPA”) polycarbonate (referred to as “polycarbonate,” or “PC”) is the top engineering thermoplastic by volume worldwide, and has inherently excellent thermal and mechanical properties. However, PC generally has deficiencies in areas such as poor processability, inadequate solvent and chemical resistance, and reduced toughness under low temperatures. A significant portion of commercial PC is blended with acrylonitrile-butadiene-styrene (“ABS”) or polyethylene terephthalate (“PET”) to improve its processability and other properties, but one or more other properties are typically compromised. The inadequate solvent and chemical resistance will cause PC to craze or crack when exposed to various common solvents or chemicals. Blending with polyolefins (“PO's”) can improve chemical resistance but PC—PO blends are unstable and delamination is an issue. Typically, relatively high loadings of compatibilizers, which in many cases have a high cost, are needed for a stable morphology, but one or more properties are compromised. Some known methods of improving low-temperature performance are blending, copolymerizing, or modifying (e.g., reactive extrusion) with polysiloxane, which is relatively expensive. Publications directed to PC's include: U.S. Pat. No. 4,532,282; U.S. Pat. No. 5,416,148; U.S. Pat. No. 5,585,434; U.S. Pat. No. 5,786,424; U.S. Pat. No. 6,329,450; U.S. Pat. No. 8,987,379; US2016/0244559 (WO 2015/052110), and the like, the disclosures of which are incorporated by reference herein. There is a need in the art for polycarbonate polymers and processes to produce polycarbonates having one or more of improved processability, chemical resistance, low-temperature properties, high heat distortion temperature, high stiffness, and reduced cost relative to polycarbonate polymers and processes known in the art.